Atmosphere analysis device



June 3, 1 969 E. T. BENNETT ATMOSPHERE ANALYSIS DEVICE Filed Oct. 10, 1966 lA/VENTO/P ELME/P 7. BENNETT A 7' TOR/V573.

United States Patent US. Cl. 23-254 8 Claims This invention relates to an atmosphere analysis device, and more particularly, to a device utilizing a chemical such as lead peroxide as a means for ascertaining an index of the activity of a pollutant such as sulfur dioxide in the atmosphere.

Measurements of sulfur dioxide in the atmosphere by the lead peroxide method are customarily made in the open air either at ground level or on a low roof away from chimneys. Devices of this nature have at times been referred to as being of the lead peroxide cylinder method. Reactivity has been defined as the weight of sulfate collected by a unit area of lead peroxide surface in a unit time, divided by the concentration of sulfur dioxide in the air. Test results with the device of the present invention have indicated that the reactivity rates disclosed heretofore are inaccurate by to percent.

The present invention begins with the basic premise that reactivity increases with relative humidity. The present invention includes means designed to maintain a substantially uniform relative humidity for the lead peroxide. This may be accomplished by utilizing capillary action of a wick, with the wick having one end portion immersed in a liquid such as water and its other end portion juxtaposed to the layer of lead peroxide.

It is an object of the present invention to provide an atmosphere analysis device which is simple, inexpensive, and more reliable than those utilized heretofore.

It is another object of the present invention to provide an atmosphere analysis device which substantially increases the reactivity.

=It is another object of the present invention to provide an atmosphere analysis device of the lead peroxide cylinder type wherein a wick is provided to maintain the lead peroxide layer moist.

Other objects will appear hereinafter.

For the purpose of illustrating the invention, there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

FIGURE 1 is a vertical sectional view of the device of the present invention.

FIGURE 2 is a sectional view taken along the line 2-2 in FIGURE 1.

Referring to the drawing in detail, wherein like numerals indicate like elements, the atmosphere analysis device of the present invention is designated generally as 10. The device 10 includes a cylinder support housing 12 having a base 14 and a top 16 interconnected by a generally annular portion 18. Portion 18 of the housing is similar to a doughnut and as will be obvious from the drawings, portion 18 is of greater circumference and diameter as compared to the base 14 and top 16. Housing 12 may be made from any one of a wide variety of materials including metals and plastics. When made from a metal, housing 12 would be preferably made from a non-corrosive lightweight material such as aluminum. When made from a plastic, housing 12 may be made from polyvinyl chloride, polyethylene, polyurethane, nylon, etc.

The housing 12 has a base 14 which is flat and in general the housing is low. Hence, the device 10 will have stability, thereby enabling it to be utilized in areas subjected to high winds. The housing 12 is filled with a liquid such as water by means of the vent plug 20. While the housing 12 is indicated in the drawings as being of one-piece construction, it obviously can be made in two halves which are thereafter bolted, fused, welded, or otherwise connected together. When the housing 12 is constructed of two mating metal halves bolted together, it is contemplated that an O-ring seal will be provided at the joint between the two mating halves.

A sleeve 22 has its lower end threadedly coupled to the inner periphery of top 16. A cup having a base 24 and a cylindrical wall 26 is provided. The diameter of wall 26 is slightly greater than the diameter of sleeve 22. A suitable gap between the outer periphery of sleeve 22 and the inner periphery of wall 26 would be approximately one-sixteenth to one-eighth of an inch. Wall 26 is provided with a large number of holes 28 disposed in a perforated zone.

A wick 30 is provided. Wick 30 is a hollow sleeve made from cotton felt or other comparable material. One end portion of the wick 30 extends to a location adjacent the base 14. The diameter of the wick 30 is chosen so that it generally follows the inner peripheral surface of sleeve 22 and can be bent back on itself so as to be disposed in the gap between sleeve 22 and the wall 26.

A layer of gauze 32 is wound around the wall 26 in overlying relationship with respect to the holes 28. The upper and lower edge portions of the gauze 32 may be retained in the predetermined position by means of rubber bands '36. Other equivalent retaining means may be substituted for the rubber bands. A layer of reactant 34 is applied to the gauze 32. The reactant 34 may be lead peroxide which is preferred as the reactant when the pollutant sought to be measured is sulfur dioxide. In place of lead peroxide, the layer 34 may be other paste materials as desired.

The paste layer 34 of lead peroxide may be made in any convenient manner and is known to those skilled in the art. Thus, layer 34 may be made as follows: Mix 8 grams of lead peroxide with 6 milliliters of gum mucilage to obtain a mixture that is easily worked. The lead peroxide should be of known reactivity. Thereafter, the mix should be immediately and evenly spread on the gauze 32 with a spatula. The surface area of the layer 34 should be a known amount such as 10 square centimeters. If the layer 34 is 10 square centimeters, then the circumference of the outer surface on wall 26 should likewise be 10 centimeters. Thereafter, water is introduced into the housing 12.

It is often desirable to locate the device 10 in a louvered housing so as to prevent the same from being tipped over by high winds. The shape of the housing 12 will enable the device 10 to be subjected to high winds without being tipped over. By capillary action, the water moves up the wick 30 and maintains the layer 34 moist. A large number of the devices 10 will be simultaneously utilized at different locations and at different distances from various sources of atmospheric pollution such as smoke stacks.

At various time intervals, such as one day, one week, one month, the gauze 32 and layer 34 will be removed and replaced with a new gauze and layer 34. Assuming that layer 34 is lead peroxide, it will combine with sulfur dioxide in the atmosphere to form lead sulfate. It will be noted that lead peroxide and lead sulfate are each insoluble in water. The amount of lead sulfate which is present on the gauze 32 after a predetermined interval is a function of the sulfur dioxide in the atmosphere. The manner in which the amount of sulfur dioxide in air may be computed based on the amount of lead sulfate is known to those skilled in the art and a discussion of the same is not deemed necessary for purposes of the present disclosure.

Heretofore, it has been noted that the layer of lead peroxide tends to flake off the gauze 32. By keeping the gauze 32 and lead peroxide 34 constantly subjected to a substantially constant amount of dampness, there is generally no tendency of the lead peroxide to flake off the gauze 3-2.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.

I claim:

1. An atmosphere analysis device comprising a housing adapted to contain a liquid therein, a hollow cylindrical wall having perforations therethrough, said wall being supported by said housing, a wick along the inner surface of said wall, said wick being of sufficient length so as to extend into said housing for contact with a liquid in the housing, and a layer of absorbent material coupled to the outer periphery of said -wall in overlying relation with respect to the perforations, whereby said layer of material may be kept moist by said wick.

2. A device in accordance with claim 1 wherein said housing is of substantially greater diameter than said wall, said layer of absorbent material being a layer of gauze, and said Wick being tubular.

3. A device in accordance with claim 1 including a sleeve having its lower end connected to said housing, said sleeve being disposed within said wall and spaced radially inwardly therefrom, a portion of said wick being disposed between said sleeve and said wall, said wall being part of a cuphaving a base, said base being above the upper end of said sleeve, and said cup being supported by the open end thereof.

4. A device in accordance with claim 1 wherein said layer of absorbent material is a guaze having a layer of lead peroxide thereon.

5. A device in accordance with claim 1 wherein said 4 housing includes a flat base connected to a top by means of a generally doughnut-shaped portion, the diameter and circumference of the doughnut-shaped portion being substantially greater than the top, said wall being coupled to said top at a location closer to the base than the upper surface of the doughnut-shaped portion.

6. An atmosphere analysis device comprising a housing adapted to contain a liquid, a hollow sleeve having one end connected to the housing so as to be in open communication with the interior of the housing, a cupshaped member surrounding said sleeve and radially spaced therefrom with the base of the cup-shaped member being juxtaposed to the other end of the sleeve, a tubular wick, one end of said wick entering into said housing, said tubular wick having its opposite end disposed in the space between the outer periphery of the sleeve and the inner periphery of said cup-shaped member, and means for introducing a liquid into the housing.

7. A device in accordance with claim 6 wherein said housing includes a base connected to a top by means of a generally doughnut-shaped portion surrounding said one end of the sleeve, with the upper surface of the doughnut-shaped portion being substantially above the top of said housing.

8. A device in accordance with claim 6 wherein the open end of the cup-shaped member is threadedly coupled to the sleeve, and the sleeve being threadedly coupled to the housing at said one end of the sleeve.

References Cited UNITED STATES PATENTS 1,725,071 8/1929 Gaby 239-515 XR 2,481,296 9/1949 Dupuy 239-515 XR 2,723,158 11/1955 Molina 239-44 MORRIS O. WOLK, Primary Examiner.

R. E. SERWIN, Assistant Examiner.

U.S. Cl. X-R. 

1. AN ATMOSPHERE ANALYSIS DEVICE COMPRISING A HOUSING ADAPTED TO CONTAIN A LIQUID THEREIN, A HOLLOW CYLINDRICAL WALL HAVING PERFORATIONS THERETHROUGH, SAID WALL BEING SUPPORTED BY SAID HOUSING, A WICK ALONG THE INNER SURFACE OF SAID WALL, SAID WICK BEING OF SUFFICIENT LENGTH SO AS TO EXTEND INTO SAID HOUSING FOR CONTACT WITH A LIQUID IN THE HOUSING, AND A LAYER OF ABSORBENT MATERIAL COUPLED TO THE OUTER PERIPHERY OF SAID WALL IN OVERLYING RELATION WITH RESPECT TO THE PERFORATIONS, WHEREBY SAID LAYER OF MATERIAL MAY BE KEPT MOIST BY SAID WICK. 